“Acoustics” has become a buzzword in recent years. As open floor plans become the norm, end users are realizing the impact on the sound of the space.

But the science of acoustics is a complicated subject, so interiors+sources
spoke with Hanson Hsu, principal and founder of Delta H Design Inc.

(DHDI). With clients including Kanye West, Universal Music Group, and
Yahoo Music, DHDI specializes in understanding the science of sound
and vibration, discovering new and innovative ways to change the ways in
which we experience acoustics.

Here Hsu provides a brief 101 on sound, vibration, and the audible
characteristics of materials to help designers find acoustic solutions.

Sound is energy riding on air molecules. Technically, it is the rarefaction
and compression of air. Think of a slinky expanded and then compressed.

Or waves in the ocean, which is energy riding on water molecules. It’s
essentially wave theory and physics.

Vibration is sound or, more accurately, energy moving through a solid
material like the ground or building materials such as wood, steel, and
drywall. Think of an earthquake.

As stated previously, sound rides on air. As the air moves through an
interior space, every material the air meets affects the timbre of the sound,
much like how an electrical signal is subject to the characteristics of the
copper cable through which it passes. Architecturally, every single
material used to construct a room has a clearly audible, and often
dramatic, effect on sound. Hence the importance of materials science
upon acoustics. How each material sounds and how it affects the air on
which sound rides is important when specifying architectural materials.

When it comes to how sound moves through these specified architectural materials, the most common vibrational concerns are HVAC,
airport, and roadway noise traveling through structural members. These